ARF, ras (p21), src, cAMP-dependent protein kinase, and the family of G-proteins, are all regulatory proteins whose cellular localization and/or activities are affected by covalent attachment of the fatty acids, myristate or palmitate. The role of post- translational covalent acylation of regulatory proteins will be examined by generating a series of mutant genes using site- directed mutagenesis. The normal and mutant cDNAs will then be expressed and proteins purified for tests of intrinsic enzymatic activities as well as the ability to participate in regulatory, protein-protein interactions. Immunocytochemistry will be used to determine the cellular localization of mutant proteins expressed in appropriate cellular systems. In addition, the mutant proteins will be tested as potential substrates or inhibitors of myristyl and palmityl transferases.